More Climate Change News

Alright folks. I’m back in the United States after spending 6 weeks in New Zealand for field camp! More on that at a later time. Special thanks to Ron for continuing to post while I was gone!

There is quite a bit of news on climate change that has been reported lately. This press release from the American Association for the Advancement of Science explains how scientists are looking back at ancient greenhouse gas emissions in order to gain an understanding of what may happen in the future.

“If you go back in time, you have to go back to the middle Pliocene before you get to see a climate that was as warm as what we are going to see in the next 50 to 100 years in our own time,” Chandler said.

Ocean temperatures rose substantially during that warming episode–as much as 7 to 9 degrees Celsius (about 12 to 16 degrees Fahrenheit) in some areas of the North Atlantic. But scientists are puzzled. The carbon dioxide levels at that time–inferred from geochemical data–were roughly comparable to our own time, approaching 400 parts per million. Today’s computer models do not predict the sort of temperature rises that occurred during the middle Pliocene, Chandler said.

Another issue raised by rapid climate change is how primary producers such as phytoplankton would respond. New research by scientists at Penn State show that phytoplankton populations have experienced rapid recovery after rapid climate change in Earth’s past.

The factors that were altered in the upper marine environment during the abrupt climate change events included increases in temperature and changes in thermal structure, changes in salinity and alkalinity, and changes in nutrient patterns and trace elements.

“In every case, changes in surface habitats resulted in transient plankton communities,” Bralower told attendees at the 2006 annual meeting of the American Association for the Advancement of Science. “Although we have a poor understanding of ancient plankton ecology, it appears that extinctions were selective and targeted more specialized and often deeper-dwelling species.”